What are they thinking of?
They are thinking of talking to their mom.
What was I thinking of?
I was thinking of getting a new job.
What is she thinking of?
She's thinking of buying a new / designer bag.
What is he thinking of?
He's thinking of going to / joining the gym.
What are they thinking of?
They are thinking of moving.
What is he thinking of?
He's thinking of retiring.
What was she thinking of?
She was thinking of cleaning her room.
What was I thinking of?
You were thinking of getting a coffee.
What were we thinking of?
We were thinking of getting married.
What are you thinking of?
I'm thinking of taking a break.